The invention relates to a sensor for detecting objects in a monitoring area.
Sensors of that type can be designed in the form of optical sensors, in particular, that are generally used to detect objects.
Sensors of that kind have suitable display units to display status messages, warning messages or the like. In the simplest case, such a display unit is comprised of a single LED, which emits a flashing or permanent light signal when a warning message is to be delivered, as an example.
The requirements on the display units are also rising along with the increasing functional scope of the sensors to the effect that complex text messages or even graphics have to be output with them. The use of single or multi-digit seven-segment displays for outputting text messages in the form of alphanumeric characters is well known. The integration of seven-segment displays of that type leads to undesirably high levels of engineering work and costs, however. Moreover, the display possibilities of the seven-segment displays for representing individual alphanumeric characters are limited.
A sensor for detecting objects in a monitoring area is known from DE 10 2011 054 247; it has a display unit that is comprised of a series of lamps with a linear configuration of lamps arranged so as to rotate around an axis of rotation running in parallel to its longitudinal axis. The series of lamps is controlled via a control unit in such a way that the columns of a matrix-type display field to be shown are individually output one after the other to the series of lamps at the clock rate of the display field and displayed with the series; the clock rate is adapted to the rotary speed in such a way that these displays complement one another to form a standing image of the display field.